In the circuit given below, the value of resistance X , when the potential difference between the points B and D is zero, will be

Step-by-step solution

P = 15 + 6 = 21   Ω ,   Q = 8 X 8 + X + 3 R = 15 + 6 × 6 6 + 6 = 18   Ω ,   S = 4 + 4 × 4 4 + 4 = 6   Ω Since potential difference across B D is zero hence it satisfies Wheatstone's Bridge condition, ∴ P Q = R S , so Q = P S R = 21 × 6 18 = 7   Ω 3 + 8 x 8 + x = 7 ⇒ x = 8   Ω